diff --git a/tests/tcp/tcp-phi1.pml b/tests/tcp/tcp-phi1.pml
index e058160..243cfd0 100644
--- a/tests/tcp/tcp-phi1.pml
+++ b/tests/tcp/tcp-phi1.pml
@@ -3,10 +3,10 @@
 // not yet implemented: phi6
 mtype = { SYN, FIN, ACK, ABORT, CLOSE, RST, OPEN }
 
-chan AtoN = [1] of { mtype };
-chan NtoA = [1] of { mtype };
-chan BtoN = [1] of { mtype };
-chan NtoB = [1] of { mtype };
+chan AtoN = [2] of { mtype };
+chan NtoA = [2] of { mtype };
+chan BtoN = [2] of { mtype };
+chan NtoB = [2] of { mtype };
 
 int state[2];
 int pids[2];
diff --git a/tests/tcp/tcp-phi2.pml b/tests/tcp/tcp-phi2.pml
index f3aa304..960a173 100644
--- a/tests/tcp/tcp-phi2.pml
+++ b/tests/tcp/tcp-phi2.pml
@@ -3,10 +3,10 @@
 // not yet implemented: phi6
 mtype = { SYN, FIN, ACK, ABORT, CLOSE, RST, OPEN }
 
-chan AtoN = [1] of { mtype };
-chan NtoA = [1] of { mtype };
-chan BtoN = [1] of { mtype };
-chan NtoB = [1] of { mtype };
+chan AtoN = [2] of { mtype };
+chan NtoA = [2] of { mtype };
+chan BtoN = [2] of { mtype };
+chan NtoB = [2] of { mtype };
 
 int state[2];
 int pids[2];
diff --git a/tests/tcp/tcp-phi3.pml b/tests/tcp/tcp-phi3.pml
index 811c8f3..35a9049 100644
--- a/tests/tcp/tcp-phi3.pml
+++ b/tests/tcp/tcp-phi3.pml
@@ -3,10 +3,10 @@
 // not yet implemented: phi6
 mtype = { SYN, FIN, ACK, ABORT, CLOSE, RST, OPEN }
 
-chan AtoN = [1] of { mtype };
-chan NtoA = [1] of { mtype };
-chan BtoN = [1] of { mtype };
-chan NtoB = [1] of { mtype };
+chan AtoN = [2] of { mtype };
+chan NtoA = [2] of { mtype };
+chan BtoN = [2] of { mtype };
+chan NtoB = [2] of { mtype };
 
 int state[2];
 int pids[2];
diff --git a/tests/tcp/tcp-phi4.pml b/tests/tcp/tcp-phi4.pml
index 8438d9f..68c2d48 100644
--- a/tests/tcp/tcp-phi4.pml
+++ b/tests/tcp/tcp-phi4.pml
@@ -3,10 +3,10 @@
 // not yet implemented: phi6
 mtype = { SYN, FIN, ACK, ABORT, CLOSE, RST, OPEN }
 
-chan AtoN = [1] of { mtype };
-chan NtoA = [1] of { mtype };
-chan BtoN = [1] of { mtype };
-chan NtoB = [1] of { mtype };
+chan AtoN = [2] of { mtype };
+chan NtoA = [2] of { mtype };
+chan BtoN = [2] of { mtype };
+chan NtoB = [2] of { mtype };
 
 int state[2];
 int pids[2];
diff --git a/tests/tcp/tcp-phi5.pml b/tests/tcp/tcp-phi5.pml
index a1bbc27..417ac59 100644
--- a/tests/tcp/tcp-phi5.pml
+++ b/tests/tcp/tcp-phi5.pml
@@ -3,10 +3,10 @@
 // not yet implemented: phi6
 mtype = { SYN, FIN, ACK, ABORT, CLOSE, RST, OPEN }
 
-chan AtoN = [1] of { mtype };
-chan NtoA = [1] of { mtype };
-chan BtoN = [1] of { mtype };
-chan NtoB = [1] of { mtype };
+chan AtoN = [2] of { mtype };
+chan NtoA = [2] of { mtype };
+chan BtoN = [2] of { mtype };
+chan NtoB = [2] of { mtype };
 
 int state[2];
 int pids[2];
diff --git a/tests/tcp/tcp-phi6.pml b/tests/tcp/tcp-phi6.pml
index 4624caa..2cf306a 100644
--- a/tests/tcp/tcp-phi6.pml
+++ b/tests/tcp/tcp-phi6.pml
@@ -3,10 +3,10 @@
 // not yet implemented: phi6
 mtype = { SYN, FIN, ACK, ABORT, CLOSE, RST, OPEN }
 
-chan AtoN = [1] of { mtype };
-chan NtoA = [1] of { mtype };
-chan BtoN = [1] of { mtype };
-chan NtoB = [1] of { mtype };
+chan AtoN = [2] of { mtype };
+chan NtoA = [2] of { mtype };
+chan BtoN = [2] of { mtype };
+chan NtoB = [2] of { mtype };
 
 int state[2];
 int pids[2];
diff --git a/tests/tcp/tcp.pml b/tests/tcp/tcp.pml
index 1780927..4e39675 100644
--- a/tests/tcp/tcp.pml
+++ b/tests/tcp/tcp.pml
@@ -3,10 +3,10 @@
 // not yet implemented: phi6
 mtype = { SYN, FIN, ACK, ABORT, CLOSE, RST, OPEN }
 
-chan AtoN = [1] of { mtype };
-chan NtoA = [1] of { mtype };
-chan BtoN = [1] of { mtype };
-chan NtoB = [1] of { mtype };
+chan AtoN = [2] of { mtype };
+chan NtoA = [2] of { mtype };
+chan BtoN = [2] of { mtype };
+chan NtoB = [2] of { mtype };
 
 int state[2];
 int pids[2];